Where did the Right to Privacy originate?

I agree with the above posters in that what we call Americans' "Right to privacy" is strongly suggested by the Constitution in the 1st, 4th and 14th Amendments, but it is never clearly or explicitly stated.

It was the court system in the United States, and especially the Supreme Court, that interpreted the Constitution in such a way that a reasonable expectation of privacy was the right of our citizenry.  There have been literally thousands of cases where evidence obtained by illegal search was deemed inadmissible in court, upholding our right to both privacy and due process, unless the government can prove reasonable suspicion that a person has committed or is going to commit a crime.

The Supreme Court has ruled on numerous occasions upholding those same lower court rulings on evidence, then expanding privacy rights into both marriage and pregnancy, ruling first in Griswold vs. Connecticut that contraception and family planning were private matters, and could not be prohibited by the State, then in Roe vs. Wade that a woman had a right to medical privacy in making decisions about her own body with regards to abortion (though they did allow for second and third trimester restrictions to stand, thus offering only limited privacy rights).

So I would have to give the nod to the Judicial Branch for defining and expanding Americans' right to privacy.